Nonstenotic Internal Carotid Arteries: Effects of Age and Blood Pressure at the Time of Scanning on Doppler US Velocity Measurements

Abstract

Internal carotid artery peak systolic velocities decrease with advancing age and increase with increasing pulse pressure. The effects of blood pressure at the time of scanning are small, but isolated systolic hypertension could cause increases in spurious velocity.

Pulsatile Flow Phantom for Ultrasound Image-Guided HIFU Treatment of Vascular Injuries

“…In our phantom, flow rates of 50-500 ml/min were achieved, with pulse rates between 62 and 138 beats/min, and peak pressures between 100 and 250 mmHg. In comparison, an average human pulse is 70 beats/min (Mohrman et al 2003), and an average flow rate in a human carotid artery is 415 ml/min (Weskott and Holsing 1997) with peak blood pressure of approximately 140 mmHg (Spencer et al 2001). The velocity and pressure profiles in the phantom could be adjusted as needed to mimic a variety of human physiological states (both normal and traumatic).…”

Toward clinical equipoise: the current case for carotid angioplasty and stent placement

“…The PSV value and visualization of plaque on gray-scale ultrasonography are the main parameters in diagnosing and classifying CA stenosis. 5,30 The use of ultrasound measurement of flow velocities to grade stenoses in the CCA and ICA is more reliable than gray-scale or color Doppler imaging alone. 5,20,30 When multiple stenoses are present (tandem lesions), the one with the greatest luminal narrowing determines the extent of hemodynamic compromise.…”

“…Among the conditions that can lead to misrepresentation of the PSV as an indication of stenosis severity are the presence of tandem lesions, discrepancy between gray-scale plaque visualization and PSV in the ICA, increased CCA velocities, hypertension, hyperdynamic cardiac state, contralateral occlusion, or low cardiac output. 11,30 In such cases, determination of the ICA/CCA PSV ratio and ICA end-diastolic velocity will provide further insight into the severity of the disease.…”

“…7,20,24,30 Additionally, the criteria for reporting and stratifying ICA stenosis vary among institutions. 29,30 In 2003, the Society of Radiologists in Ultrasound published recommendations E. I. Levy, et al for using ultrasonography in the diagnosis and interpretation of atherosclerotic stenosis of the ICA.…”

“…Levy, et al for using ultrasonography in the diagnosis and interpretation of atherosclerotic stenosis of the ICA. 30 The panel found that this modality is not effective in stratifying lesions with less than 50% stenosis; thus, they recommended that these lesions be classified in a single category ("Ͻ 50% stenosis"). After analyzing the literature, the panel developed ultrasonography thresholds for the stratification of ICA stenosis (Table 1).…”